In-process semiconductor devices may be formed by physically and electrically attaching semiconductor dice (e.g., stacks of semiconductor dice) to an active surface of a wafer of semiconductor material. The semiconductor dice may be at least laterally surrounded by a molding material. When the wafer-level assembly comprising the in-process semiconductor devices and wafer is exposed to elevated temperatures, for example, during back end processing as well as debonding of the wafer level assembly from a carrier substrate, the wafer-level assembly may warp beyond acceptable tolerances. For example, materials of the molding material, the semiconductor dice, and the wafer may exhibit different coefficients of thermal expansion, such that heating or cooling causes the molding material and semiconductor material of the semiconductor dice and wafer to expand or contract at different rates, resulting in warpage of the wafer-level assembly. When the wafer-level assembly is warped, handling and processing may be difficult, if not impossible, to accomplish without handling and processing equipment damaging the wafer.
Attempts have been made to minimize warpage of wafer-level assemblies comprising molding material through selection of molding materials, as the volume of molding material relative to the total volume of other materials (e.g., silicon and metals) in a wafer-level assembly is a dominant factor. However, existing molding materials have proven to promote warpage to one degree or another in excess of acceptable tolerances under exposure to elevated temperatures. For example, differences in coefficients of thermal expansion between the molding materials and semiconductor wafers may cause warpage of 1 mm, 2 mm, or even greater. As the warpage of the semiconductor wafer increases, the likelihood that the wafer will be damaged during handling and processing, such as during surface grinding, debonding from a carrier substrate, and cutting to singulate individual semiconductor devices from one another, increases.